You can now view change sets before updating your stacks in AWS CloudFormation. This helps you understand the resource-level changes (e.g. adding, deleting, or modifying instances) which CloudFormation will apply to your live stack when you are updating your AWS infrastructure. Previously, you could not see the specific changes that CloudFormation would apply to your stack before submitting changes.

You can create one or multiple change sets for your existing stack by submitting a modified template, new parameter values (e.g. the instance type for your EC2 instances), or both. The change set will display a list of proposed changes, such as which resources CloudFormation will add, modify, or delete. You can then instruct CloudFormation to implement the changes to your stack.

You can get started with change sets using the CloudFormation console, AWS CLI, or CloudFormation API. Learn more about changes sets by reading our documentation.